LAUSR

rete ridges of the epidermis. In 45% of the selected nevi, we could observe some dysplastic nevus characteristics; specifically, we saw low-grade atypia in 32.7% of cases and moderate atypia in only 2% of cases, while severe atypia was never observed. The majority of patients with cytological atypia were women (40.3%; P = 0.04), which is well recognizable in our semantic map analysis (Illustration 1). The exact causes of the overall site-specific or situationspecific histological characteristics, are not well known, but it is possible that the contribution of external factors, such as minor repeated trauma (by walking or by shaving) and ultraviolet exposure, as well as intrinsic factors, such as age and hormonal influences, may influence their development. Considering nevi alone, we did not find any significant differences among demographic criteria and the type of lesion between upper and lower leg and between male and female patients. In conclusion, the “classical” melanocytic nevus of the legs is a heavily pigmented lentiginous compound nevus, with an acanthotic and hyperkeratotic epidermis, a normal nevoid dermal component, mild-to-moderate inflammation, pigment incontinence, and some architectural “dysplastic-nevus-characteristics” (fibroplasia, unsharp lateral borders). Most of these characterizing features can be identified already at low power (“scanning”) magnification. The results of our study show that in ML on the legs there are only a few overlapping characteristics between nevi and melanoma, and the classic characteristics for differentiating nevi from melanoma can be safely applied to lesions on the leg.